Typical ECC error correction systems used in magnetic disc drives correct error bursts that occur relatively frequently and that are of short in duration in comparison to the sector size. The ECC system operates on a single data sector in which the error burst occurs. The ECC system performs corrections on-the-fly to the user data, which is to say that the corrections are completed without significantly interrupting the flow of the data stream as it is sent from the magnetic disc drive to a host system.
There are, however, types of errors that occur in magnetic disc drives that are larger. Traditionally, these types of errors have been corrected using creative reread (read retry) mechanisms that rely on modifying read channel parameters or head re-positioning schemes to recover the faulty data. If the error is such that these retry schemes are not effective, then the drive has exhausted its ability to recover the data. The user's data is lost.
Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.